Harbours everywhere?

[frenzyfol]

civpedia "Harbors give 50% extra trade route yield"

I remember someone saying that it can actually be detrimental to build a harbor in some cities because they actually alter the city trade route choices by making the harbored city a stronger choice for high yeild trade routes.
i.e. If a high payoff trade route is going to your capital and being multiplied by bureaucracy if you build a harbor in a different city it can steal the capitals trade route and the result is less payoff empire wide.

Firstly, is this true?

And most importantly would building harbors in EVERY city be beneficial (forget the health bonus, I'm talking $$).

[Jaybe]

Build harbors where you have highest science/gold multipliers (or maybe where you need the health benefits). Trade routes are based on city size, and harbors will artificially enhance the size of the city they are in (for trade route allocation).

If you have a coastal city that you are not going to build the commerce buildings (as in a production city), don't cannibalize your commerce cities' trade routes by building a harbor there.

Source: Blake (I don't think it was Dale). Some old thread. The civopedia description is supposedly inaccurate.

[Willem]

Hmmm, I learn something new every day. I had never considered this before, I just tried to build Harbours in all of my coastal cities. I guess I'll have to change my approach.

[Yosho]

Although, someone else made a thread pointing out that by building harbors everywhere, you may be stealing trade routes from AI's.

(shrug)

If you have harbors in your little cities and your big cites, the big cities should still get the better trade routes, right? It's only bad if you have them in your littles cities but not your big cities

[Aro]

If you build harbours in all of your coastal cities, every one will have the same bonuses... So, nothing really changes.

I'm probabily wrong, but...

[wodan11]

As a general rule your "smaller" cities are your production cities, and these will build the harbor before your "large" cities (which will be your commerce cities), for 2 reasons which result from their higher hammer input. (1) They're "caught up" with everything else you wanted to build, thus you're ready to queue up the harbor as soon as it's available, and (2) they build it faster if both start at the same time.

The question then becomes is it better to have a harbor in a "smaller" city and no harbor in the "larger" one, or should you wait?

So, you take a route which is slightly better (probably something like 4 commerce vs 2) and switch cities. The 4 becomes a 2 and the 2 probably becomes a 3 + 50%, total 6.5.

Even if it's a bigger disparity, such as 6 vs 1, the 6 probably becomes a 3 and the 1 becomes a 3 or 4 + 50% = total 9.

Either way it's an improvement.

Wodan

[Verrucosus]

That's true as far as coastal cities competing for trade routes against each other are concerned. However, from what I understand, a harbour can be detrimental (overall) when its construction in a large coastal city attracts a good trade route away from an inland city that may have better multipliers from buildings and wonders and where you cannot compensate by building a harbour there.

I think a better documentation of the trade route mechanism in the manual or at least in the civilopedia would have been helpful. It's probably wishful thinking, but a detailed civilopedia update for the game concepts section in the final patch would be an excellent finishing touch for the game.

Verrucosus

EDIT: Sorry, I didn't see wodan's post. My first paragraph was a comment on Aro's preceding post.

[frenzyfol]

Thanks for the input.

In my current game EVERY single one of my cities is coastal. I'm also expansive (1/2 price harbors).

The way I understand it is that providing my economic cities get the harbors first, then I can build them in all the other cities. This way I will be stealing trade routes from the AI (not from myself) and the final result will be a nationwide increase in trade route yield.

[wodan11]

It's my understanding that it's not possible to "steal trade routes from yourself". You're simply exchanging routes.

As for getting better routes from the AI... you'll get them whenever you build the harbors in your economic (commerce) cities.

So, building harbors in your non-economic cities first will NOT hurt you in the slightest.

Anyway, that's MY understanding. This obviously contradicts that of others, so if any third party wants to chime in, go for it.

Wodan

[snoopy369]

Clarification:
You can NEVER steal trade routes from the AI. Trade routes are independent of other civs' trade routes entirely - to the point that you can have routes with a civ that can't have routes the reverse direction theoretically.

Your trade route pool is the following:
1 for every AI city you have trade access to and open borders with
Infinite for all of your cities

You allocate the trade pool in the order of largest benefit to smallest benefit to your various cities.

The problem with harbors comes particularly if you have your wall street city in a non-coastal city; it's vital that city gains the largest trade possible. In a largely coastal empire this isn't a significant problem, but in a largely land empire with a few coastal cities, you can do harm.

Generally, though, the 'don't build harbors everywhere' rule comes from the fact that harbors have a cost - and in a non-coastal game, you will not gain their cost back ever (if you weight the hammers appropriately for potential future gains of other uses). I'd build harbors in a largely coastal empire, and in any city that is one of my largest; and just make sure a coastal city is your WS city

[johnmcd]

They don't need a better explanation, just an intuitive system.

[snoopy369]

Originally posted by wodan11
It's my understanding that it's not possible to "steal trade routes from yourself". You're simply exchanging routes.

As for getting better routes from the AI... you'll get them whenever you build the harbors in your economic (commerce) cities.

So, building harbors in your non-economic cities first will NOT hurt you in the slightest.

Anyway, that's MY understanding. This obviously contradicts that of others, so if any third party wants to chime in, go for it.

Wodan

The issue is that a trade route between a size 10 city and another size 10 city, as opposed to the same route between a 10 city and your size 2 city, have different values - pop of the cities matters, as do other factors (distance, for example). It's particularly relevant if you have not enough trade routes to go around from foreign civs, so you have a bunch of 3-4 value routes and a bunch of 1 value routes internally; going from 4 down to 1 in a large city, where that 1 will never go up, and then from 1 up to 2 in a small city, will net cost you money; and from 1 up to 3 in a medium city will still have some cost for the harbor offsetting the 0.5 net gain. As long as you have plenty of foreign routes, it's not going to cost you much, and will generally benefit you (again as long as your WS city has a harbor).

[wodan11]

Is the 4 in your example pre-modifiers or post-?

Wodan

[snoopy369]

Pre-modifiers.

[wodan11]

Question: when, exactly, does the game decide to switch routes?

It must be post-modifiers, or else the Harbor wouldn't make a whit of difference.

So, the 2nd city (the 1, in this example), would be compared to... let's pick a number out of a hat, and say +100% modifier... 4 + 100% = 8.

The 2nd city now has a harbor (+50%). The 1 becomes 1.5. (I believe with BtS the rounding is now done after all commerce is accumulated, instead of along the way.)

1.5 !> 8, therefore, the route would not be switched.

Wodan